NASA RELEASES DEEP IMPACT MISSION STATUS REPORT March 25, 2005
NASA's Deep Impact spacecraft completed the commissioning phase of the mission
and has moved into the cruise phase.
Deep Impact mission planners have separated the spacecraft's flight operations
into five mission phases. Cruise phase will continue until about 60 days before
the encounter with comet Tempel 1 on July 4, 2005.
Soon after launch on Jan. 12, 2005, Deep Impact entered the commissioning phase.
During that phase, the mission team verified the basic state of health of all
subsystems and tested the operation of science instruments. The spacecraft's
autonomous navigation system was activated and tested using the moon and Jupiter
as targets.
The spacecraft's high gain antenna, which will relay images and data of the
cometary collision, was activated and is operating properly. A trajectory
correction maneuver was performed, refining the spacecraft's flight path to
comet Tempel 1. The maneuver was so successful that a second one planned for
March 31 was cancelled.
Another event during commissioning phase was the bake-out heating of the
spacecraft's High Resolution Instrument (HRI) to remove normal residual moisture
from its barrel. The moisture was a result of absorption into the structure of
the instrument during the vehicle's last hours on the launch pad and its transit
through the atmosphere to space.
At completion of the bake-out procedure, test images were taken through the HRI.
These images indicate the telescope has not reached perfect focus. A special
team has been formed to investigate the performance and to evaluate activities
to bring the telescope the rest of the way to focus. Future calibration tests
will provide additional information about the instruments' performance.
The Deep Impact spacecraft has four data collectors to observe the effects of
the collision: a camera and infrared spectrometer comprise the High Resolution
Instrument; a Medium Resolution Instrument (MRI); and a duplicate camera on the
Impactor Targeting Sensor (ITS). They will record the vehicle's final moments
before it is run over by comet Tempel 1 at approximately 23,000 mph. The MRI and
ITS are performing as expected.
"This in no way will affect our ability to impact the comet on July 4," said
Rick Grammier, Deep Impact project manager at NASA's Jet Propulsion Laboratory
(JPL), Pasadena, Calif. "Everyone on the science and engineering teams is
getting very excited and looking forward to the encounter."
Dr. Michael A'Hearn of the University of Maryland, College Park, Md., added, "We
are very early in the process of examining the data from all the instruments. It
appears our infrared spectrometer is performing spectacularly, and even if the
spatial resolution of the High Resolution Instrument remains at present levels,
we still expect to obtain the best, most detailed pictures of a comet ever
taken."
Deep Impact is comprised of two parts, a flyby spacecraft and a smaller
impactor. The impactor will be released into the comet's path for the planned
high-speed collision. The crater produced by the impactor is expected to range
from the width of a house up to the size of a football stadium and be from two
to 14 stories deep. Ice and dust debris will be ejected from the crater
revealing the material beneath.
Along with the imagers aboard the spacecraft, NASA's Hubble, Spitzer and Chandra
space telescopes, along with the largest telescopes on Earth, will observe the
effects of the material flying from the comet's newly formed crater.
An intimate glimpse beneath the surface of a comet, where material and debris
from the formation of the solar system remain relatively unchanged, will answer
basic questions about the formation of the solar system. The effects of the
collision will offer a better look at the nature and composition of these
celestial travelers.
The University of Maryland provides overall mission management for this
Discovery class program. Project management is handled by JPL. The spacecraft
was built for NASA by Ball Aerospace & Technologies Corporation, Boulder, Colo.
RELEASE: 05-086
Dolores Beasley
Headquarters, Washington
(Phone: 202/358-1753)
D.C. Agle
Jet Propulsion Laboratory, Pasadena, Calif.
(Phone: 818/ 393-9011)